Door-operated electric switch

ABSTRACT

A door-operated electric switch for refrigerators and the like comprises a housing for recessed mounting in a door jamb, the housing containing switch contacts that are actuated by a switch button that projects through the housing and is depressed upon closing of the door. The contacts are actuated as a result of a relatively small initial increment of closing movement of the door. Further closing of the door maintains the contacts in their door-closed condition. The housing has a barrier that inhibits passage of water to the switch contacts and also holes that drain water from the housing to prevent accumulation of water and possible short-circuiting of the switch contacts.

United States Patent Horecky i [54] DOOR-OPERATED ELECTRIC SWITCH [72]inventor: Stanley V. llorecky,.0ak- Park, Ill.

[731-Assignee: Molex Incorporated, Downers Grove, Ill.

22 Filed: Jan. 7, 1971 [21] Appl. No.2 104,680

[52] US. Cl ..200/6L76, 200/168 G [51] Int. Cl. .L ..H0lh 3/16 [58]Field of Search ..200/6l.62- 6l.84,

200/159 A, 61.76, 61.62, 164 R, I64 A, I68 G, 119R, 119B, ll9EL, ll9L,'ll9TS, 119 WG, 168 R; l74/37;'337/l 12 [56] References Cited UNITEDSTATES PATENTS 3,586,810 6/1971 Brown .Q ..200/159R 2,289,816 7/1942Werner ..........200/61.76 2,238,630 4/1941 Reamer ..200/61.82

2,761,936 Verkuil ..200/15'9A [151 3,694,595 1 1 Sept. 26, 19723,030,479 4/1962 Ehrlich et al ..200/168 R 3,260,814 7/l966 Turnbull..200/l68R 522,972 7/1894 Cuttriss ..337/328 Primary Examiner-Robert K.Schaefer Assistant Examiner-M. Ginsburg Attorney-Olson, Trexler, Wolters& Bushnell [5 7] ABSTRACT A door-operated electric switch forrefrigerators and the like comprises a housing for recessed mounting ina door jamb, the housing containing switch contacts that are actuated bya switch button that projects through the housing and is depressed uponclosing of the door. The contacts are actuated as a result of arelatively small initial increment of closing movement of the door.Further closing of the door maintains the contacts in their door-closedcondition. The housing has a barrier that inhibits passage of water tothe switch contacts and also holes that drain water from the housing toprevent accumulation of water and possible short-circuiting of theswitch contacts.

' 10 Claims, 9 Drawing Figures PATENTEDSEHB 1912 3.694 595 SHEET 2 OF 2DOOR-OPERATED ELECTRIC SWITCH BACKGROUND OF THE INVENTION This inventionrelates generally to electric switches, and more particularly, todoor-operated switches of the type primarily intended for refrigerators,although the switch is capable of use in other environments as well.

In refrigerator door switches as in other door switches, the switchbutton or actuator isoperated by the door and therefore has a closedposition that is determined by the closed position of the door relativeto the frame upon which the door is mounted. In the case of refrigeratordoors, the fit between the door and the door frame tends to vary widelyamong different units due the presence of a sealing gasket on the doorthat serves to take up clearance between the door and frame when theformer is closed. moreover, the clearance inany particular refrigeratorunit may vary somewhat in use as the gasket tends to flatten out.Because of this, the travel of the door switch actuator and its positionwhen the door is closed tends to be different in various units and alsotends to change as the refrigerator is used. As a result it sometimeshappens that the door switch becomes unreliable in its operation.

A further problem in refrigerator door switches renders in the possiblecollection of moisture and resultant shortcircuiting of switch contacts.This can come about by reason of condensation or from cleaning therefrigerator. In the latter case it should be noted that while theswitch housing is recessed in the door frame the opening in the housingthrough which the actuator or button projects is usually substantiallyflush with the door frame and not water tight. As a result a wet rag orsponge passed over the door frame may tend to exude water into theswitch housing causing a short circuit and/or corroding the switchcontacts.

OBJECTS AND SUMMARY OF THE INVENTION It is an object of this inventionto provide a switch of the door-operated type that is reliable inoperation despite variations in tolerances in the fit between the doorand the door frame. The switch is particularly suitable for arefrigerator. In one form of the invention the switch may be used toturn on the interior light of the refrigerator when the door is opened.In another form of the invention the switch may be used to turn off anair circulating fan in the refrigerator when the door is opened so as toreduce the discharge of cold air from the refrigerator when the door isopened. A refrigerator may embody two switches, one according to each ofthe aforesaid forms of the invention.

It is a further object of this invention to provide a switch of the typestated which is constructed so as to prevent or substantially inhibitthe collection of moisture therein which might tend to corrode theswitch contacts or cause a short circuit thereof.

In accordance with the foregoing objects the switch comprises a housingfor recessed mounting in a door frame and switch contacts having aclosed condition and an open condition. In the fan switch form ofinvention. the switch contacts are closed when the door is closed andare open when the door is open; in the interior light switch form of theinvention, the contacts are open when the door is closed and are closedwhen the door is open. A door-operated switch actuator is pivoted in theswitch housing and projects outwardly therefrom. The actuator has a camfor engagement with one of the contacts to move that contact into or outof wiping engagement, as the case may be, with the other or fixedcontact during an initial increment of travel of the door from its opento its closed position. This increment may be a minor fractional part ofthe movement of the actuator from its door-open to its door-closedposition. Once the contacts have been actuated during this initialincrement of door movement (and consequent movement of the switchactuator) further movement of the door to its closed position servesmerely to maintain the switch contacts in their door-closed condition.

The housing has a transverse dam or wall that constitutes a waterbarrier between the contact points of the switch contacts and theopening in the housing through which the actuator projects. The base ofthe housing between the barrier and said opening has one or morepassageways by which water may be drained from the housing.

BRIEF DESCRIPTION OF THE FIGURES In the drawing:

FIG. 1 is a front elevational view of a refrigerator embodying doorswitches constructed in accordance with the present invention;

FIG. 2 is a fragmentary sectional view, on an enlarged scale, takenalong line 2-3 of FIG. 1, and showing a switch in which the switchcontacts are open when the refrigerator door is open;

FIG. 3 is a fragmentary sectional view, on an enlarged scale, takenapproximately along line 3-3 of FIG. 2;

FIG. 4 is a fragmentary sectional view taken along line 4-4 of FIG. 3but showing the full switch assembly as seen from the section line;

FIG. 5 is a fragmentary sectional view similar to FIG. 4 and showing theswitch in the door-closed condition;

FIG. 6 is a fragmentary sectional view similar to FIG. 4 and showing aswitch of the type wherein the switch contacts are closed when therefrigerator door is open;

FIG. 7 is a fragmentary sectional view of the arrangement of FIG. 6 butshowing the switch in the doorclosed position;

FIG. 8 is a perspective view of the switch housing of the presentinvention, the housing cover being omitted so as to illustrate theinterior of the switch housing; and

FIG. 9 is a perspective view of the switch button or actuator that formspart of the present invention.

DETAILED DESCRIPTION Referring now in more detail to the drawing thereis shown a refrigerator 2 having a generally rectangular door frame 4having a door opening 6. A door 8 is secured to the door frame 4 at theopening 6 by hinges 10, 10 whereby the door 8 is swingable about avertical axis to and from its open and closed positions shownrespectively in full lines and broken lines in FIG. 2. The edge of thedoor 8 may be provided with a gasket 12 for sealing against the doorjamb 14.

The door jamb 14 has an opening 16 for receiving a plastic switchhousing 18. A pair of opposed cantilever arms 20, 20 are integral withthe sides 28, 30 of the housing and are provided for retaining thehousing in place in the opening 16. The arms 20, terminate at their freeends in fingers 22, 22 such that when the housing 18 is inserted throughthe opening 16, the arms 20, 20 are pressed toward the housing 18. Thespring pressure of the fingers 22, 22 press the fingers against the edgeof the opening 16. The switch housing 18 is provided at its forward endwith a marginal flange 24 that is adapted to lie flush against theexterior surface of the door jamb l4 and thus limit the extent ofinsertion of the housing 18 into the opening 16. By use of a smallscrewdriver or like tool for prying under the flange 24, the housing maybe removed from the opening 16.

The housing 18 constitutes a portion of either a normally open switch Sshown in FIGS. 2-5 or a normally closed switch shown in FIGS. 6 and 7.The'normally closed switch S may be used to control a fan within therefrigerator while the switch S may be used to control one or moreinterior lights within the refrigerator such that when the refrigeratordoor 8 is opened the switch S shuts off the fan while the switch S turnsof the interior light or lights in the refrigerator. Conversely, whenthe refrigerator door 8 is closed the switch S turns off the interiorlight or lights while the switch S restarts the fan.

The housing 18 also comprises a bottom wall 26 and f a back 32 which aremarginally secured to the sides 28, I 30. The housing 18 also comprisesa top cover 34 which is secured to the housing walls 28, 30, 32 in anysuitable manner, which may include a depending flange 35 that engagesthe inside surfaces of the sides 28, 30. At the junction of the side andback wall 32 the housing is formed with a vertical slot 36 for receivinga movable contact 38. The contact 38 includes a terminal 40 thatprojects upwardly through the cover 34 for attachment to a conductor inthe fan circuit of the refrigerator. The contact 38 is in the form ofa-flat tempered spring blade of brass having angularly related legs 42,44 that are joined by an arcuate apex portion 46. At its free end theleg 44 has a silver contact point 48. Approximately at the junction ofthe back wall 32 and theside 28 the housing 18 if formed with anadditional vertical slot 50 for receiving a fixed contact 52 which has aterminal 53 that projects upwardly through the housing cover 34 forconnection with the other wire of the fan circuit. The fixed orstationary contact 52 is also a flat blade and outwardly of the slot 50the contact 52 angles toward the leg 42, terminating in a contact point54 that faces the contact point 48.

Intermediate the back 32 and the front marginal flange 24 and alsoforwardly of the contact point 54 is a wall or dam 56 that projectsupwardly from the bottom wall 26 and extends between the sides 28, 30.The wall 56 has a clearance slot 57 for receiving the legs 42, 44 of themovable contact 38. Adjacent to the wall 56 but forwardly thereof thebottom wall 26 is formed with drain passageways 58, 58 and through whichwater may be drained from the part of the housing forwardly of 60 shownin FIG. 9, the actuator 62 is generally sector shaped and includesspaced apart plates 64, 66 and integral opposed hinge pins 68, 69 thatextend laterally of the plates 64, 66 at the narrow end of the actuator62. The actuator 62 is pivotally mounted within the housing 18 adjacentto the opening 60. In this regard the hinge pin 68 is pivotally mountedat one end in a hole 70 (FIG. 8) in the bottom wall 26 while the otherhinge pin 69 is joumalled in a trunion 72 on the inside face of themarginal flange 24. When the cover 34 is assembled with the housing thecover 34 overlies the upper axial end of the hinge pin 69. A torsionspring 74 is disposed between the plates 64, 66 at the narrow end of theactuator. One end 76 of the torsion spring 74 abuts the actuator 62radially outwardly of the hinge pins while the other end 78 of thetorsion spring is positioned between the side wall 28 and a shoulder 80that projects upwardly from the bottom 26 offset from the side 28. Thetorsion spring 74 biases the actuator 62 of the switch S to itsdoor-open position, namely as shown in FIGS. 2 and 4. However, when thedoor 8 is swung from its open position shown in full lines in FIG. 2 toits closed position shown in broken lines in FIG. 2 and also in FIG. 5,the door 8 presses against the actuator 62 in opposition to the force ofthe torsion spring 74 to move the actuator 62 to its fully recessed ordoor-closed position within the housing 18.

Between the plates 64, 66 the actuator 62 is integrally formed with acam 82 for moving the movable contact 38 and thereby actuate the switch.In the dooropen position of the actuator 62, the cam 82 is spaced fromthe movable contact 38. The cam surface 84 provides a small radius tip85 (FIGS. 6 and 9) and an adjacent surface 87 of large radius such thatduring an initial part of an initial increment of movement of theactuator, the latter first moves into engagement with the movablecontact 38. In the remainder os said initial increment of movement ofthe actuator 62 form its dooropen position to its door-closed positionthe movable contact 38 is moved such that the contact points 48, 54 arequickly brought into engagement with a wiping contact by the engagementof the cam surface tip portion 85 with the apex portion 46 of thecontact 38. Further movement of the actuator 62 to its door-closedposition serves simply to maintain the contact points 48, 54 in contactdue to engagement of the surface portion 87 with the contact 38. Thisinsures that the contact points 48, 54 will close before the gasket 12engages the door jamb 14 despite wide variations among differentrefrigerator units in the final position of the door in its closedposition relative to the door jamb. The amount of overtravel of theactuator 62 after the contact points 48, 54 have engaged may vary butsuch overtravel is preferably a substantial part of the total travel ofthe actuator. Viewed another way, the initial increment of travel of theactuator 62 of switch S from the door-open position (FIG. 4) to aposition in which the contact points 48, 54 engage is only a minorfractional part of the total arcuate travel of the actuator.

In cleaning the refrigerator it is not uncommon for a wet rag or spongeto be passed over the door jamb 14 in the region of the switch S,. Insome instances, water may be forced into the housing 18 through theopening 60. Such water can drain out of the passageways 58, 58.

In the switch S of FIGS. 6 and 7, the housing 18 and actuator 62 are thesame as in the switch 8,. However, the switch S differs from the switchS in that the switch S is normally closed (e. g. when the refrigeratordoor is open) to close the interior light circuit. Thus, themovablecontact 38a is self biased by its spring temper such that its contactpoint 48a is normally (door open) in engagement with the contact point54a on the fixed contact 52a. It should be noted that the contact points48a, 52a are respectively on oppositesides of their associated contacts38a, 52 as compared to the disposition of the contact points 48, 54.Thus, when the actuator 62 of the switch S moves from the door-openposition (FIG. 6) toward the door-closed position (FIG. 7) an initialincrement of movement causes the cam surface portion 85 to move thecontact switch contacts in said housing and having a closed conditionand an open condition, said switch contacts including a movable contact,and a rockable dooroperated actuator onsaid housing and having adooropen position and a door-closed position, spring means biasing saidactuator to its door-open position, said actuator having cam means inengagement with said movable contact when the actuator is in itsdoor-closed position and biasing said movable contact to a position inwhich said contacts are in one of said conditions, the contacts being inthe other condition when said actuator is in its door-open position,said cam means and said movable contact having coacting surface meansshaped such that in an initial increment of movement 'of said actuatorfrom its-door-open position toward its doorclosed position the cam meansmoves said movable contact to a position in which said contacts are insaid one condition, and in the remaining movement of said actuatortoward its door-closed position the cam means continues to biassaid'movable contact to cause said switch contacts to remain in said onecondition, said initial increment being a minor fractional part of themovement of said actuator from its door-open position to its door-closedposition, said cam means and said movable contact being spaced apartwhen the actuator is in its door-open position so that in an initialpart of said initial increment of movement, the actuator moves intoengagement with the movable contact.

2. A switch according to claim 1 in which said movable contact hasangularly related legs joined by an arcuate apex portion and said apexportion is engaged by said cam means.

3. A door-operated switch comprising a housing having means for mountingthe same in a door frame, switch contacts in said housing and having aclosed condition and an open condition, said switch contacts including amovable contact, and a rockable dooroperated actuator on said housingand having a dooropen position and a door-closed position, spring meansbiasing said actuator to its door-open position, said actuator havingcam means in engagement with said movable contact when the actuator isin its door-closed position and biasing said movable contact to aposition in which said contacts are in one of said conditions, thecontacts being in the other condition when said actuator is in itsdoor-open position, said cam means and said movable contact havingcoacting surface means shaped such that in an initial increment ofmovement of said actuator from its door-open position toward itsdoorclosed position the cam means moves said movable contact to aposition in which said contacts are in said one condition, and in theremaining movement of said actuator toward its door-closed position thecam means continues to bias said movable contact to cause said switchcontacts to remain in said one condition, said initial increment being aminor fractional part of the movement of said actuator from itsdoor-open position to its door-closed position, said housing having anopening through which said actuator projects, a wall in said housingbetween said opening and the region of engagement of said contacts, andsaid housing having passage means between said wall and said opening fordraining fluid from the housing.

4. A switch according to claim 3 in which said wall has a slot throughwhich said movable contact projects.

5. A door-operated switch comprising a housing having means for mountingthe same in a door frame, switch contacts in said housing and having aclosed condition and an open condition, said switch contacts including amovable contact, and a rockable actuator door-operated on said housingand having a door-open position and a door-closed position, spring meansbiasing said actuator to its door-open position, said actuator havingcam means with a cam surface for engagement with said movable contactwhen the actuator is in its door-closed position andbiasing said movablecontact to a position in which said contacts are in one of saidconditions, the contacts being in the other condition when said actuatoris in its door-open position, said cam surface including a first surfaceportion that is spaced from said movable contact when the actuator is inits door-open position and which initially engages said movable contact,and an adjacent second surface portionfor subsequently engaging saidmovable contact, said first surface portion having a smaller radius ofcurvature than that of said second surface portion.

6. A door-operated switch comprising a housing, switch contacts in saidhousing, means carried by said housing for actuating said switchcontacts, an opening in said housing and through which said meansprojects, and a wall in said housing and forming a fluid barrier betweensaid opening and the region of engagement of said contacts, said housinghaving passage means between said wall and said opening for drainingfluid from said housing.

7. A switch according to claim 6 in which said housing includes meansfor mounting the same in a door frame, said opening being approximatelyflushwith said frame.

8. A switch according to claim 6 in which said switch contacts include amovable contact that projects through said wall.

9. A door-operated switch according to claim 6 in which said housing hasa bottom wall and a cover opposite to said bottom wall, the wall formingthe fluid barrier projecting from said bottom wall toward said cover.

10. A-door-operated switch according to claim 9 in which said switchcontacts includes a movable switch contact projecting through said wallforming the fluid barrier, and said actuating means includes a camportion engaging said movable switch contact.

1. A door-operated switch comprising a housing having means for mountingthe same in a door frame, switch contacts in said housing and having aclosed condition and an open condition, said switch contacts including amovable contact, and a rockable dooroperated actuator on said housingand having a door-open position and a door-closed position, spring meansbiasing said actuator to its door-open position, said actuator havingcam means in engagement with said movable contact when the actuator isin its door-closed position and biasing said movable contact to aposition in which said contacts are in one of said conditions, thecontacts being in the other condition when said actuator is in itsdoor-open position, said cam means and said movable contact havingcoacting surface means shaped such that in an initial increment ofmovement of said actuator from its door-open position toward itsdoor-closed position the cam means moves said movable contact to aposition in which said contacts are in said one condition, and in theremaining movement of said actuator toward its door-closed position thecam means continues to bias said movable contact to cause said switchcontacts to remain in said one condition, said initial increment being aminor fractional part of the movement of said actuator from its dooropenposition to its door-closed position, said cam means and said movablecontact being spaced apart when the actuator is in its door-openposition so that in an initial part of said initial increment ofmovement, the actuator moves into engagement with the movable contact.2. A switch according to claim 1 in which said movable contact hasangularly related legs joined by an arcuate apex portion and said apexportion is engaged by said cam means.
 3. A door-operated switchcomprising a housing having means for mounting the same in a door frame,switch contacts in said housing and having a closed condition and anopen condition, said switch contacts including a movable contact, and arockable door-operated actuator on said housing and having a door-openposition and a door-closed position, spring means biasing said actuatorto its door-open position, said actuator having cam means in engagementwith said movable contact when the actuator is in its door-closedposition and biasing said movable contact to a position in which saidcontacts are in one of said conditions, the contacts being in the othercondition when said actuator is in its door-open position, said cammeans and said movable contact having coacting surface means shaped suchthat in an initial increment of movement of said actuator from itsdoor-open position toward its door-closed position the cam means movessaid movable contact to a position in which said contacts are in saidone condition, and in the remaining movement of said actuator toward itsdoor-closed position the cam means continues to bias said movablecontact to cause said switch contacts to remain in said one condition,said initial increment being a minor fractional part of the movement ofsaid actuator from its door-open position to its door-closed position,said housing having an opening through which said actuator projects, awall in said housing between said opening and the region of engagementof said contacts, and said housing having passage means between saidwall and said opening for draining fluid from the housing.
 4. A switchaccording to claim 3 in which said wall has a slot through which saidmovable contact projects.
 5. A door-operated switch comprising a housinghaving means for mounting the same in a door frame, switch contacts insaid housing and having a closed condition and an open condition, saidswitch contacts including a movable contact, and a rockable actuatordoor-operated on said housing and having a door-open position and adoor-closed position, spring means biasing said actuator to itsdoor-Open position, said actuator having cam means with a cam surfacefor engagement with said movable contact when the actuator is in itsdoor-closed position and biasing said movable contact to a position inwhich said contacts are in one of said conditions, the contacts being inthe other condition when said actuator is in its door-open position,said cam surface including a first surface portion that is spaced fromsaid movable contact when the actuator is in its door-open position andwhich initially engages said movable contact, and an adjacent secondsurface portion for subsequently engaging said movable contact, saidfirst surface portion having a smaller radius of curvature than that ofsaid second surface portion.
 6. A door-operated switch comprising ahousing, switch contacts in said housing, means carried by said housingfor actuating said switch contacts, an opening in said housing andthrough which said means projects, and a wall in said housing andforming a fluid barrier between said opening and the region ofengagement of said contacts, said housing having passage means betweensaid wall and said opening for draining fluid from said housing.
 7. Aswitch according to claim 6 in which said housing includes means formounting the same in a door frame, said opening being approximatelyflush with said frame.
 8. A switch according to claim 6 in which saidswitch contacts include a movable contact that projects through saidwall.
 9. A door-operated switch according to claim 6 in which saidhousing has a bottom wall and a cover opposite to said bottom wall, thewall forming the fluid barrier projecting from said bottom wall towardsaid cover.
 10. A door-operated switch according to claim 9 in whichsaid switch contacts includes a movable switch contact projectingthrough said wall forming the fluid barrier, and said actuating meansincludes a cam portion engaging said movable switch contact.